Ngptv Vita

Ngptv
File:Ngptvvita.jpg
General
Author	yifanlu
Type	Developments
Version	2017
License	CC-BY-4.0
Last Updated	2017/12/30
Links
Download
Website
Source

Ngptv is HDMI adapter driver for the Vita.

What is Ngptv?

This is an attempt at making an HDMI adapter for the Vita. It does not work because the ADV7533 does not support the auto clock stopping that the Vita uses to save battery on the MIPI DSI clock. There are two ways of getting it to work.

1. Replace the ADV7533 with another part that supports MIPI clock going from HS to LP mode when the data lanes are not in use. There are no other DSI to HDMI part, but you might get away with stacking a DSI to eDP and eDP to HDMI for example. Another way is to use a FPGA and convert the signals manually.
2. Creating some custom part to "filter" the stopped clock to a continuous clock. There does not appear to be any off-the-shelf part that does this and I've tried looking into re-purposing jitter correctors but they don't work because they average out the clock signals instead of locking on to the highest frequency.

Both are too much work for me to consider doing, so I will leave this non- working project as is. Included are two designs. First is ngptv, which is supposed to be a small board that fits inside the Vita.

Due to the design constraints of the ADV7533 (small pitch BGA) which requires > 6 layers and the small size requirement of all components, it does not seem feasible for me to prototype (too expensive and I don't have the right equipment to assemble). Additionally, the ADV7533 is a NDA part that requires a HDMI license to buy.

The second design is ngptv lite which is designed to connect directly to a B-LCDAD-HDMI daughterboard. This $30 board contains a ADV7533 and was originally designed to work with a ST evaluation board. We instead connect it to the ngptv lite which has a microcontroller to interface with ADV7533 as well as a redriver for MIPI DSI. Using a FFTP-07-D-03.85-01-N cable, this connects to a breakout board placed inside the Vita that brings in the MIPI DSI signals from the exposed testpoints. The first version lacked the redriver, which seemed to still work (to the extent that it works if you manually set the Vita's MIPI clock to not use LP mode, which breaks the on screen video).

These designs are provided as-is under CC 4.0.

External links

• Yifan - https://yifan.lu/2017/12/31/vita-hdmi-mod-attempt/
• Github - https://github.com/yifanlu/ngptv